Vesicoureteral reflux in the primate. IV. Infection as cause of prolonged high-grade reflux.

High-grade reflux commonly lasts longer than moderate reflux, which disappears with maturation of the ureterovesical junction. It is known that ureteral function is affected by urinary tract infection from studies in experimental animals, as well as through clinical findings in patients with upper tract infection. Whether infection might affect the ability of the ureter to prolong high-grade reflux was questioned. This observation might explain why high-grade reflux does not disappear as rapidly as moderate reflux in children with recurrent urinary tract infections. Vesicoureteral reflux was produced surgically in combination with bladder neck obstruction using infant monkeys. The reflux thus produced was high grade with ureteral dilation and caliectasis. In the group of animals in which the bladder neck obstruction was relieved surgically, the reflux rapidly disappeared. In the other group, a bladder infection was produced with Escherichia coli at the time of release of the bladder neck obstruction. The reflux lasted significantly longer, an average of 18 months. Therefore, it appears that treatment of urinary tract infection rather than vesicoureteral reflux is the most important therapy.